Cured-in place liner material and methods and systems for manufacture

Abstract

A liner tube for repairing existing pipes is provided. The liner tube is sufficiently flexible to lie substantially flat under its own weight thereby defining an upper portion and a lower portion. The liner tube includes an inner layer, an outer layer disposed around the inner layer, a first intermediate layer disposed between the inner layer and the outer layer, the first intermediate layer being wrapped around the inner layer to overlap itself and define a first overlap portion in the upper portion, and a second intermediate layer disposed between the first intermediate layer and the outer layer, the second intermediate layer being wrapped around the first intermediate layer to overlap itself and define a second overlap portion in the lower portion. The first and second intermediate layers include a porous material and the inner layer includes material substantially impermeable to liquids.

What is claimed is:  
     
       1. A method of making a liner tube having sufficient flexibility to lie substantially flat in a first state and to be substantially circular in cross section in an expanded state, the method comprising:
 wrapping a first intermediate layer around a flexible tube, the first intermediate layer overlapping itself to define a first overlap portion at a first circumferential position of the circular cross section when the liner tube is in the expanded state; 
 wrapping a second intermediate layer around the first intermediate layer, the second intermediate layer overlapping itself to form a second overlap portion at a second circumferential position of the circular cross section when the liner tube is in the expanded state, the first circumferential position and the second circumferential position being at least 120 degrees apart circumferentially, 
 wrapping a third intermediate layer around the second intermediate layer, the third intermediate layer, the third intermediate layer overlapping itself to form a third overlap portion, wherein the second overlap portion and the third overlap portion do not overlap each other and 
 wrapping an outer layer around and adjacent to the third intermediate layer to surround the first and, second and third intermediate layers between the outer layer and the flexible tube; and 
 at least the first and second intermediate layers comprising an absorbent material and the flexible tube comprising a substantially impermeable material; 
 
       wherein the flexible tube comprises an absorbent layer with a silicone coating formed on an inner surface of the flexible tube, wherein the absorbent material layer is adjacent to the first intermediate layer. 
     
     
       2. The method of  claim 1 , wherein longitudinal edges of the silicone coated flexible tube are secured with silicone glue, wherein the longitudinal edges are oriented along the length of the flexible tube. 
     
     
       3. The method of  claim 1 , further comprising impregnating the first and second intermediate layers with a curable liquid. 
     
     
       4. The method of  claim 1 , wherein at least one of the first and second overlap portions are free-floating and impermeable to gases and liquids such that the liner is gas/liquid tight in response to curing. 
     
     
       5. The method of  claim 1 , wherein the outer layer is translucent to visible light and impermeable to light in at least a portion of the ultraviolet spectrum.